Grace Potter has played Mobile before, but never as a BayFest headliner. She says she's excited about the possibility of reaching some new listeners. (Williams Hirakawa photo, courtesy of Hollywood Records)

First, during a phone interview about her upcoming appearance at BayFest 2012, I mentioned that one of the other top acts on Sunday, Oct. 7, is Al Green.

“Al Green!” she exclaimed. “You just said the magic words.”

But before she could make her plans to catch his show, I clarified that the Rev. Green is scheduled to hit the Miller Lite/Wind Creek Casino Stage at 7:15, the exact time Potter and her band, the Nocturnals, are supposed to fire up the Coca-Cola Stage a few blocks away.

“So Al is on one stage and I’m on another? Oh, noooooo!” she said.

“That’s too bad,” she said good-naturedly. “I don’t ever want to stand up against him. Man!”

It’ll work out. There should be enough fans to go around: Green has certainly earned a loyal following over the course of his lengthy career, and Potter has been a rising star for about three years now, a popular act on the jam-music festival circuit who was a standout at the Hangout Music Fest in 2010 and 2011.

But on her way up, she found a receptive fan base in Mobile, where she’s appeared at Soul Kitchen, the BlueGill and the Swamp Room at Felix’s Fish Camp. So she’s not just blowing smoke when she says she’s looking forward to BayFest, which will put her on the biggest stage she’s ever had in the Port City.

“I’m so excited. I love Mobile” she said. “We keep coming back because it’s such a great place. BayFest is awesome, so I’m very excited about it.”

Weekend passes are $45, available through www.bayfest.com with no service charge. They also are available through 5 p.m. Friday at Wind Creek Casino & Hotel in Atmore; Regions Bank branches in the Florida Panhandle, coastal Alabama and coastal Mississippi; and Circle K stores throughout south Alabama and in the Florida Panhandle.

It could be argued that Potter, Pretty Lights and Michael Franti, all Hangout Fest stars, are bringing a little of the younger event’s freshness to the time-tested BayFest formula. But Potter said she doesn’t necessarily see it that way.

“Whatever works,” she said. “Everybody has their own version of what the experience is going to be. But I think they’re such different places, Mobile and Gulf Shores, that I think the spirit of the town and sort of the vibe of Mobile will permeate and overwhelm any other comparison.”

(For his part, Bobby Bostwick, president of the BayFest board, said that Potter and Franti are acts that he'd gladly have booked before now, if factors such as the timing of the festival and their touring schedules had meshed.)

One thing BayFest promises, given the eclectic nature of its lineup, is an audience of browsers who’ll have the chance to sample new music. That’s an appealing place to be, both as a performer and a listener, she said.

“That’s one of the great things about a festival, is that discovery phase,” she said. “And some of what I love about coming to a festival is being surprised by the music that I wasn’t there to see. You know, you go to see Radiohead or Paul McCartney or one of the big names at Coachella or Bonnaroo or whatever, and then you get completely sidelined by these amazing pieces of music being made by people that you didn’t know about.”

Some bands make big adjustments for festivals. Potter said the Nocturnals don’t go overboard to tailor their show to newcomers.

“It depends on the day, it depends on the audience, it depends on the show,” she said. “For the most part, we don’t really cater our set or what we do to an audience. But there’s times, where for instance, if it’s a rainy day and people are kind of bummed, you can, like, bring the spirit out in them and like make that rain into celebration. There are certain things you can do with your show that can kind of remind people that you’re a human too, and that we’re all feeling a certain way together. … You just kind of have to get on the same page with everybody.”

The main thing she’d like to get across is that the band shouldn’t be pigeonholed based on its earliest music. Potter & the Nocturnals burst to notice with sultry rock that drew heavily on a swaggering ‘70s sensibility. More recently, particularly with the 2012 album “The Lion The Beast The Beat,” the group has branched out in new directions – more ballads, more thoughtful songwriting, even touches of country courtesy in part of Potter’s collaborations with Kenny Chesney.

That’s no accident: Potter wanted to push herself out of the comfort zone and take some risks.

“We started this record over a year ago,” Potter said. “The process of writing it took way longer than usual, and I really pained myself in making sure that the recording was exactly what I wanted it to be, even at one point during the record, stopping the process of making the record and stepping away from it a little while. I don’t usually do that. Usually we just jam into our record process. Usually we just jump right into the studio, and put the record out and then we’re done. This was a different approach, and a scary one, too. So that’s definitely changed. That shift has been mostly exciting. A little terrifying, but ultimately exciting.”

The wild ride continues, she said. Appearing on Chesney’s song “You and Tequila” was only part of their crossover: She also played to his fans.

The upshot: You’re going to get more than brash numbers like “Paris (Ooh La La).” You’re also going to hear material that’s deeper, harder to categorize, such as “Stars” and “Never Go Back.”

“I hope that they come to realize that we’re not what they thought,” Potter said. “So often people think that we kind of have a handle on what we do, or who we are, or what kind of music we play. And they’re usually pleasantly surprised at the diversity and also sort of dynamic range that we have.

“I really love surprising people. And every time people kind of think they’ve got us hammered out, we take a very sharp left turn. That’s something that we do onstage and offstage, and in the studio and all over the place. That’s what I hope people take away from it, is that there’s an original sound that we continue to grow and expand upon.”

Making this point is, at least at times, an exhilarating challenge, she said.

“We just came off this wild stadium tour with Kenny Chesney and Tim McGraw, which brought us to all the major cities and major markets,” she said. “The stadiums, with 50 or 60 thousand people a night, was really quite an adventure, I have to say.”

That unusual pairing is just a sign of the times, she said.

“There’s a lot of crossover, and some cross-pollination, and that’s actually how I came to be on that Kenny Chesney song,” she said. “Everything has changed, nothing is what it used to be. And the expectation that the fan has for the music is growing at like warp speed, which is a good thing and a bad thing. Because is there ever a time to just chill out and breathe?”